Which term describes a link between qubits where changing one instantly affects the other?

Which term describes a link between qubits where changing one instantly affects the other?

• A. Noise
• B. Post quantum cryptography
• C. Entanglement
• D. Sycamore

Answer: (C)

Entanglement is a special connection between qubits in which the state of each qubit cannot be described independently of the other. When you measure or manipulate one qubit, the joint state collapses in a way that instantly fixes the outcome of the other, no matter how far apart they are. For example, two qubits in a maximally entangled state yield perfectly correlated results when measured in the same basis: if the first reads 0, the second will read 0; if the first reads 1, the second will read 1. This instantaneous correlation is a hallmark of entanglement, though it can’t be used to send information faster than light. Entanglement is a resource for quantum computing and communication, enabling phenomena like teleportation and superdense coding. The other terms don’t describe this: noise is unwanted disturbance, post-quantum cryptography concerns cryptographic schemes secure against quantum attacks, and Sycamore is the name of a quantum processor, not the phenomenon itself.

Entanglement is a special connection between qubits in which the state of each qubit cannot be described independently of the other. When you measure or manipulate one qubit, the joint state collapses in a way that instantly fixes the outcome of the other, no matter how far apart they are. For example, two qubits in a maximally entangled state yield perfectly correlated results when measured in the same basis: if the first reads 0, the second will read 0; if the first reads 1, the second will read 1. This instantaneous correlation is a hallmark of entanglement, though it can’t be used to send information faster than light. Entanglement is a resource for quantum computing and communication, enabling phenomena like teleportation and superdense coding. The other terms don’t describe this: noise is unwanted disturbance, post-quantum cryptography concerns cryptographic schemes secure against quantum attacks, and Sycamore is the name of a quantum processor, not the phenomenon itself.